There is a trend in exercising and body-building toward more concentrated exercises designed to isolate and intensively work individual muscles or muscle groups. In keeping with this trend, manufacturers of exercise and body-building equipment have designed entire lines of specialty equipment with each piece of equipment dedicated to a particular muscle or muscle group. Two obvious problems with such equipment are that a great deal of money is required to obtain all of the equipment needed for a full body workout, and a great deal of space is required to store and operate all of the necessary equipment. Additionally, such equipment rarely provides any mechanism to ensure that the person using the equipment is not shifting the exercise load away from the intended muscle or muscle group, thus defeating the purpose of the specialty equipment. The present invention addresses these problems and others by providing a relatively inexpensive and compact apparatus suitable for reliable exercise of the abdominal, lower back, and lateral oblique muscle groups.